When you complete the planetary strikes with someone in your fire team they count as three strikes, not one. At least that's been my experience. If you do not create a Titan you will be missing out on 45 Grimoire score. That's 15 for enemy kills as a Titan, 15 for crucible kills as a Titan, and 15 for Titans killed in crucible. you would be able to acquire the 15 for Titans killed in crucible using your warlock or Hunter. However, you're not able to acquire these 15 points because you have never created a Titan. Sorry I didn't respond to this earlier. I didn't see your post or missed the notification.